Blog de Victroniko


electrónica, DIY y más...

Repair: Sony Bravia KLV-37L500 TV


*Note: the following applies to ALL Sony TVs with EX2T chassis and L500 in the model name: KLV-26L500A, KLV-32L500A, KLV-37L500A etc. It MIGHT apply to other variants but I can't make any claim to it.




It's been a while since I repaired these 2 TV sets (same modes, different faults). I don't have many photos of the process, so it won't be a long entry. Rather it can be seen as a support guide in case of finding similar faults on same-model Bravias.



Teardown: T012 Bluetooth TWS Earphones


Some time ago, I bought these Bluetooth TWS headphones on Aliexpress, for my personal use. Unfortunately the size wasn't comfortable for me, they just keep popping out of my ears. Before saying goodbye, let's see what's inside ...

Let's start with the charging case:


The case is responsible for storing and, at the same time, recharging the internal battery of each earphone. It contains a small PCB with a charge controller IC, a 450mAh (??, unmarked) battery, and 2 pairs of "pogo-pins" that make contact with each earphone for charging. If we look at the back of the PCB, we can see that it was designed for different combinations of components, depending on the need.



MP3402C - Bluetooth headset charge controller IC (PDF, chinese)

Then we proceed to open one of the earphones...


Very carefully, until dissassembly is complete.


The level of miniaturization is incredible: the 40mAh battery is smaller than a fingernail, and the PCB is only 5mm wide. We can see the antenna is of the "chip" type, not printed on the same circuit (better signal in theory). With the help of a microscope we can identify the main SOC:


DCFB14D7B - SOC Bluetooth, unknown (no info)

I was unable to find information about this SOC on internet. The seller says that the product is Bluetooth 5.0, and my cellphone is 4.1 therefore I cannot corroborate if it is 5.0 or not... What baffled me though, is the chip logo: it looks suspiciously similar to ABell, a Chinese manufacturer of relatively good radio transmitters and related gear.

If we look at their website, we can't find any info on IC manufacturing, only assembled products ... Are we facing plagiarism, or they make SOCs but do not mention/advertise it? For example, Sunplus/GeneralPlus are well known for having a business structure that often allows you to identify a chip as their own, but prevents you from finding out exactly which filial it comes from. This may be the case, maybe not.

For now, all that remains is to reassemble everything, and give it to someone with bigger ears :)


A new blog? In 2019?

Let's see ... this is my first blog, and I really don't know how to start. I think the most sensible thing is to explain why a blog in these times of social networks, Instagram and those things.

Over the years, my hobby has been electronics. I tend to visit flea markets looking for old & new stuff, something that piques my curiosity ... Partly for fun and partly for teh monies: many of the things I buy in bad condition, I do repair and sell for a profit  (giving a second life to something that could end up in the trash, polluting the planet even more).

I realized something. Despite having done many things, I do not have a record of what I do, which could serve me as well as others who seek the same knowledge...

And that's why this blog :)

Little by little I will upload all kinds of information ... teardowns, guides, photographs and the things that happen to me. Because memory is fragile and knowledge should be shared, don't you think?